ISO

ISO 4921 Knitting — Basic concepts — Vocabulary

The agreed names for knitted structures and the machinery that makes them. A vocabulary standard rather than a test method, which is why it is cited so widely and argued about so little.

Number

ISO 4921

Committee

ISO/TC 38

Status

active

Equivalents

Body	Number	Equivalence	Deviation
CEN	EN ISO 4921	IDT	CEN adopts the standard unchanged under this designation, which is the name it is cited by across the European Union. Recorded so that a specification written in European terms reaches the document this register already holds.

Verification coverage

Not yet checked: ASTM, AATCC, BIS, SAC, JIS, EN, DIN — an absent row here does not mean no equivalent exists.

What this standard is for

Where it is used

In specifications and technical packs wherever a knit structure has to be described unambiguously across a supply chain that spans several languages.

Why it matters

Most knit specification disputes are definitional — two parties using one word for different structures. A named vocabulary is what makes a technical pack enforceable rather than suggestive.

What to watch for

Mills and buyers often use trade names for structures that this standard names differently. Where the contract cites the standard, the standard wins.

Calculators that implement this

• Circular Knitting Specific Energy, Cost per Kilogram & Carbon
• Elastane Plating Draft, Content Percentage & Retraction Force
• Knit Tube Slitting: Open Width, Trim Loss & Marker Fit
• Knitted Fabric GSM Predictor
• Knitting Fault Locator: Repeat Spacing to Feeders and Needles
• Knitting Order Allocation, Machine Count & Slack to the Due Date
• Positive Feeder Slippage, Loop Length Error & Barre Spacing
• Rib & Interlock Loop Transfer Strain, Tightness Limit and Speed Cost
• Stitch Cam Setting Window, Tightness Factor & Fabric Weight
• Stitch Length & Course Length Estimator

Buy the official copy from ISO

Metadata only — purchase the standard from the issuing body.